Dry-sealing envelope



April 19, 1938.k v.,E. HEYwooD DRY SEALING ENvELoPE Filed Oct. 2, 1936 e; lWaco-7 JPNJ ' non-adhesive in character.

- with dry-sealing adhesive areas.

Patented Apr. 19, 1938 UNITED sTATEs PATENT or-FlcE DRY- SEALIN ENVELOPE Application October 2, 1936, Serial No. 103,737

13 Claims.

The present invention relates to dry-sealing envelopes or containers, i. e., envelopes that are adapted to be sealed by bringing areas coated with dry-sealing adhesive into non-moistened contact.

Oneextremely simple form of dry-sealing envelope is characterized by the provision of parallel bands of dry-sealing adhesive applied to the seal ap and body of the envelope at substantially equal distances from the fold line of the seal flap, so that sealing is effected by merely folding over the iap, to bring the adhesive areas into engagement. A While such -envelopes can be packed iiat, with their seal ilaps extended, difculties arise when the adhesive is applied out to the free edges of the flaps. Withthe adhesive coated margins of the extended flaps in close overlying relation, as in a pack of envelopes, the flaps exhibit a tendency to adhere to each other along their edges, so that the flap adhesive is damaged when an envelope is removed from the pack. In order to overcome this tendency for adhesive coated edges to stick together, it has been proposed to apply the dry-sealing adhesive at an appreciable distance from the edge of any envelope portion, as shown in Lindgren Patent No. 1,945,648, issued February 6, 1934, but obviously such an expedient requires special yadhesive-applying equipment, which adds to the cost of manufacture.

According to the present invention, the above described difficulties that have been encountered in packing dry-sealing envelopes with extended flaps, are entirely overcome by turning over the adhesive coated edges to form beads that are This procedure permits the dry-sealing adhesive to be applied up to the edge of any envelope portion, in the usual manner, and then after beadingto be packed flat Without any possibility of the overlying adhesive coated portions becoming stuck together.

The above and other advantageous 'features ofl the invention will hereinafter more fully appear from the following description, considered in connection with the accompanying drawing, in which:-

Fig. 1 is a plan-view of an envelope provided Fig. 2 shows the envelope of Fig. 1, formation of a bead along one edge, in accordance with the present invention.

Fig. 3 is a sectional view on an enlarged scale, showing the manner of packing the envelopes.

Fig. 4 shows the envelope of Flg. 2, in sealed condition.

with thev Fig. 5 is a sectional view on an enlarged scale, along the line 5-5 of Fig. 4.

Referring to Fig. l, the envelope comprises opposed walls I and 2, with a seal ap 3 extending from the wall I. 'I'he wall 2 and the flap 3 are 5 provided with parallel bands of dry-sealing adhesive l and 5 that are disposed at equal distances from a light score line 6 between the flap 3 and wall 2. By the term dry-sealing adhesive, is meant any adhesiie which,.when in a dry condition, has the property of adhering to itself upon non-moistened contact, although 't will not so adhere to uncoated areas of the materials commonly employed in the manufacture of envelopes, or other containers.

'I'he bands of adhesive 4 and 5 are applied up to the edges of the wall 2 and ilap 3 and, obvious-- ly, the adhesive can be applied to the blank from which the envelope of Fig. 1 is made, either before or after folding the same. It is to be noted that the band of adhesive 5 on the ap 3 is somewhat wider than the band of adhesive 4, and after the adhesive 5 has been applied to the ap 3, the edge of the flap is turned over upon itself, to form a bead 1 extending longitudinally of the ap.

In forming the bead 1, the margin of the flap 3 that has been coated with the dry-sealing adhesive 5is turned over on itself, so that opposed 'adhesive coated portions of the flap are brought into engagement along a narrow zone. This results in forming a bead that is adhesively se cured and cannot turn back, so that the iiap 3 is bounded along its longitudinal edge by a nonadhesive margin of appreciable width, and of double the thickness of the envelopematerial.

As a result of the formation of the bead 1, it is possible to pack the envelopes of Fig. 2 with their seal flaps 3 extended, as shown in Fig. 3. With the envelopes so packed, it is evident that the beads 1 will tend to separate the aps 3 along their longitudinal edges, so that there is no possibility of the adhesive 5 on different flaps sticking together, even though the pack of envelopes be subjected to considerable pressure. While the adhesive 5 extends to the short side edges of the aps 3, the double thickness of the beads 1 serves to hold these edges apart, so as to prevent any adhesion therebetween.

When it is desired to utilize the envelope of Fig. 2, it is an easy matter to load the same, owing to the fact that the flap 3 is already extended and has not been previously folded, as with the usual envelope provided with grml that requires moistening. When the envelope has been loaded, the light score line 6 permits the flap l to be readily folded over, so as to bring the adhesive 5 into engagement with the adhesive I. Sealing is quickly .and effectively accomplished upon the application of pressure to the overlying dry-sealing adhesive areas, it being noted that the bead 1 terminates beyond the inside margin of the adhesive l, as shown in Fig. 5. The extension of the bead 1 beyond the engaged adhesive areas, in a sealed envelope, makes it possible to insert a finger nail under the bead, for the purpose of pulling apart the adhesive coated areas, should it be desired to open a sealed envelope without destroying the seal said material back on itself to bring portions of the I adhesive Ainto contact along a narrow marginal zone of much less width than the application of said adhesive.

2. An envelope having an application of drysealing adhesive extending up to an edge of the envelope material, with a narrow bead formed by adhered portions of said material along said edge.

3. An envelope providing a seal flap having an application of dry-sealing adhesive extending up to an edge thereof, with a bead formed by turning a narrow marginal portion of said flap back on itself along said edge.

4. An envelope providing a seal nap having an application of dry-sealing adhesive extending up to an edge thereof, with a bead formed by turning a marginal portion of said ap back on itself to bring portions of the adhesive into contact along said edge, said bead having a width such that the major portion of said flap adhesive is exposed.

5. An envelope providing a seal flap having an application of dry-sealing adhesive extending up to an edge thereof, with a narrow bead formed by adhered marginal portions of said flap along said edge.

6. An envelope providing an unfolded seal flap coextensive with an envelope wall, said flap having an application of dry-sealing adhesive extending up to an edge thereof, with a bead formed by turning a narrow marginal portion of said flap back on itself along said edge. I

7. An envelope providing an unfolded seal flap coextensive with an envelope wall, said flap having an application of dry-sealing adhesive extending up to an edge thereof, with a bead formed by turning a marginal portion of said flap back on itself to bring portions of the adhesive into contact along said edge and said bead having a width such that the major portion of said flap adhesive is exposed.

8. An envelope providing an unfolded seal iiap coextensive with an envelope wall, said iiap having an application of dry-sealing adhesive extending up to an edge thereof, with a bead formed by adhered marginal portions of said flap along said edge and said bead having a width such that the major portion of said iiap adhesive is exposed.

9. A pack of envelopes constructed as set forth in claim 1.

10. A pack of envelopes constructed as set forth in claim ,1, with the beads of the seal iiaps serving to prevent engagement between the adhesive coated edges of said flaps.

11. Flexible material for containers having an application of dry-sealing adhesive extending up to an 'edge thereof, with a bead formed by turning said material back on itself along said edge, -I

said bead having a width such that the major portion of said adhesive is exposed.

12. Flexible material for containershaving an application of dry-sealing adhesive extending up to an edge thereof, with a bead formed by turning a narrow marginal portion of said material back on itself to bring' portions of the adhesive into contact along said edge.

13. An envelope having one wall and a free flap provided with areas of dry-sealing adhesive, said flap adhesive area being of greater width than said wall adhesive area, with the adhesive coated margin of said flap folded over upon itself long a narrow zone to provide a bead of such width as to render said dry-sealing adhesive areas substantially equal.

VINCENT E. HEYWOOD. 

